A vehicle is essentially equipped with a brake system for braking. Recently, various types of systems have been suggested to provide a more powerful and stable braking force.
Examples of the brake system include an anti-lock brake system (ABS) that prevents slippage of a wheel during braking and a brake traction control system (BTCS) that prevents slippage of a drive wheel during sudden start or sudden acceleration of a vehicle, and an electronic stability control system (ESC) that stably maintains the running state of the vehicle by controlling a brake hydraulic pressure by combining ABS and BTCS.
Generally, an electronic brake system includes an actuator that receives an electric signal of a braking force of a driver from a pedal displacement sensor that detects a displacement of a brake pedal when the driver steps on the brake pedal, and supplies pressure to a wheel cylinder.
An electronic brake system equipped with such an actuator is disclosed in European Patent EP 2 520 473. According to the disclosed document, the actuator is provided to generate a brake pressure by operating a motor according to a pedal force of a brake pedal. At this time, the brake pressure is generated by converting a rotational force of the motor into a linear motion and pressing a piston.